The present invention relates to a method and apparatus for placing sutures in soft tissue with an ability to create a variable mattress stitch (e.g., to control the distance between sutures placed within tissue or to place a mattress stitch across torn tissue). The methods and devices described herein may also improve the ability to place a stitch or suture deeper within tissue when compared to conventional methods. Although methods and devices described herein make reference to arthroscopic repair of torn rotator cuffs, the principles of the devices and methods may be applied to any soft tissue application.
Traditional suturing of body tissues is a time consuming aspect of most surgical procedures. Many surgical procedures are currently being performed where it is necessary to make a large opening to expose the area of, for instance, the human body that requires surgical repair. There are instruments that are becoming increasingly available that allow the viewing of certain areas of the body through a small puncture wound without exposing the entire body cavity. These viewing instruments, called “endoscopes”, can be used in conjunction with specialized surgical instrumentation to detect, diagnose, and repair areas of the body that were previously only able to be repaired using traditional “open” surgery. In the past, there have been many attempts to simplify the task of driving a needle carrying suture through body tissues to approximate, ligate and fixate them. Many prior disclosures, such as described in U.S. Pat. No. 919,138 to Drake et al., employ a hollow needle driven through the tissue with the suture material passing through the hollow center lumen. The needle is withdrawn, leaving the suture material in place, and the suture is tied, completing the approximation. A limitation of these types of devices is that they are particularly adapted for use in open surgical procedures where there is ample room for the surgeon to manipulate the instrument.
Others have attempted to devise suturing instruments that resemble traditional forceps, such as U.S. Pat. No. 3,946,740 to Bassett. These devices pinch tissue between opposing jaws and pass a needle from one jaw through the tissue to the other jaw. Graspers then pull the needle and suture material through the tissue. A limitation of these designs is that they also are adapted primarily for open surgery, in that they require exposure of the tissues to be sutured in order that the tissue may be grasped or pinched between the jaws of the instrument. This is a severe limitation in the case of endoscopic surgery.
The term “endosurgery” means “endoscopic surgery”, or surgery performed using an endoscope. In conjunction with a video monitor, the endoscope permits the surgeon to remotely visualize the operative site. Operations using an endoscope are significantly less invasive when compared to traditional open surgery. Patients usually return home the next day, or in some cases, the same day of the endosurgical procedure. This is in contrast to standard open surgical procedures where a large incision divides the muscle layers and allows the surgeon to directly visualize the operative site. Patients may stay in the hospital for 5 to 6 days or longer following open surgery. In addition, after endosurgical procedures, patients return to work within a few days versus the traditional 3 to 4 weeks recuperative period at home following open surgery.
Access to the operative site using endosurgical or minimally invasive techniques is accomplished by inserting small tubes, known as trocars, into a body cavity. These trocars have a diameter of, for example, between 3 mm and 30 mm and a length of about 150 mm (6 inches). There have been attempts to devise instruments and methods for suturing within a body cavity through these trocar tubes.
Previous instruments for suturing within a body cavity are described in U.S. Pat. No. 4,621,640 to Mulhollan et al.; U.S. Pat. No. 4,935,027 to Yoon; U.S. Pat. Nos. 4,923,461 issued May 8, 1990 and U.S. Pat. No. 4,957,498 issued Sep. 18, 1990 to Caspari; U.S. Pat. No. 4,836,205 to Barrett; Garman et al in U.S. Pat. No. 5,499,991; U.S. Pat. Nos. 5,312,422 and 5,474,565 issued to Trott; the entirety of each of which is incorporated by reference.
Less invasive arthroscopic techniques are beginning to be developed in an effort to address the shortcomings of open surgical repair. Working through small trocar portals that minimize disruption of the deltoid muscle, a few surgeons have been able to reattach the rotator cuff using various bone anchor and suture configurations. The rotator cuff is sutured intracorporeally using instruments and techniques such as those previously described. This creates a simple stitch instead of the more desirable mattress or Mason-Allen stitch. Rather than thread the suture through trans-osseous tunnels which are difficult or impossible to create arthroscopically using current techniques, an anchor is driven into bone at a location appropriate for repair. The repair is completed by tying the cuff down against bone using the anchor and suture.
Early results of less invasive techniques are encouraging, with a substantial reduction in both patient recovery time and discomfort. However, as mentioned, this approach places only one loop of suture in the cuff for each anchor, reducing the fundamental strength of the repair. The knots in the tendon can be bulky and create a painful impingement of the tendon on the bone. This is because the knots end up on top of the cuff, in the sub-acromial space, and have the opportunity to rub on the acromion as the arm is raised. Because non-absorbable suture materials are used for these types of repairs, the suture and associated knots are not absorbed into the body, and hence provide a constant, painful reminder of their presence. The devices described herein are adaptable to effect the placement of a mattress stitch in grasped tissues by placing each end of the mattress stitch simultaneously, or allowing the medical practitioner to control the distance between the suture in the mattress stitch. Such a feature allows the mattress stitch to be placed across torn tissue or increase the span of the stitch. U.S. Pat. No. 5,431,666 to Sauer et al. discloses a suture instrument used to sequentially pull first and second suture lengths through tissue.
The devices and methods described herein are adaptable to place sutures precisely and controllably while making provision for needle retrieval when using endoscopic techniques by giving a medical practitioner the option of placing a mattress stitch of a pre-determined width or by allowing the medical practitioner to control the width of the stitch. In addition, variations of the methods and devices described herein incorporate features on the suturing device allowing for pulling tissue farther into the device to allow placement of the stitch deeper into the tissue.
Accordingly, although devices described herein are capable of arthroscopically creating a mattress stitch in soft tissue to increase the soft tissue pullout strength of the repaired tissue, the principles described may be applied to alternate stitching techniques or other tissue fixation techniques as well.